(a) Field of the Invention
This invention relates to an anchor device for use in securing different types of structures on a ground surface and more particularly, but not by way of limitation, to an anchor device used for supporting building foundations, poles, signs, and other types of structures typically mounted or formed on a ground surface and requiring an enhanced foundation support.
(b) Discussion of Prior Art
Heretofore there have been a variety of different types of helical plate bearing anchors mounted on solid steel bar shafts and pipe shafts with plate helices that are drilled into soil and used as tension, compression and lateral force resisting members.
Also, there are many types of hollow drill rods and drill shafts used for circulating water, drill mud and the like during a drilling operation. The drill rods and shafts can be used with grout in forming tiebacks, mini-piles, rock anchors, soil nails and other micro pile uses. The usual exterior diameter of the rods and shafts are less than 2 inches.
Further, there are various types of auger tools made in the United States. The auger tools are used for excavating holes and may be used for collecting soil samples. This type of tool may have either a solid or hollow shaft with a disposable drill head. Also flight augers have continuous helices along the length of the shaft. Because of the expense of this type of auger, the auger is generally removed from a drill hole and not left in place to be used with grout in forming a mini-pile.
Still further, many steel piles are installed today using pipe of various sizes and weights. The load carrying capacity of this type of pile is usually developed by skin friction and/or point bearing. The steel piles are driven by a pile driving hammer or by boring a hole and placing grout around the exterior of the steel pile received in the hole.
In U.S. Pat. No. 5,575,593 to Raaf, a method and apparatus for installing a helical pier with pressurized grouting is disclosed. The patent describes the forming of grout nodules attached to an exterior of a pier column. The pier column includes a bracket for securing the column to a building foundation. The Raaf pier column is not designed to be reusable nor is it used for extracting fluids from a subsurface.
In U.S. Pat. No. 4,009,582 to LeCorgne, a method is described for forming a caseless concrete pile using a hollow pipe, a connector and a tubular driving mandrel. In U.S. Pat. No. 3,512,366 to Turzillo, a hollow auger for drilling holes is disclosed. The auger described in the Turzillo patent is withdrawn from the hole leaving a steel rod with drill bit in place with concrete poured therearound for forming a concrete pier.
In U.S. Pat. Nos. 4,492,493 and 4,756,129 to Webb and 3,115,226 to Thompson, Jr. different types of ground anchors and apparatus are described. Also, U.S. Pat. Nos. 4,998,849 to Summers, 3,961,671 to Adams et al. and 4,678,373 to Langenbach, Jr. disclose different types of driving apparatus and methods of shoring structures.
None of the above patents disclose or teach the unique combination of structure and functions of the subject anchor device having a combination of external pipe sections with helices thereon and internal pipes sections with a rock bit for drilling into an underground rock formation for providing greater anchor stability.